1. Field of the Invention
The present invention relates to a navigation system, and more particularly, to a system and method for sharing position information between a plurality of navigation terminals using a mobile communication system, and displaying positions of other navigation terminals, together, in one navigation terminal.
2. Description of the Related Art
In recent years, the number of users of a vehicle equipped with a navigation system providing a road guidance service based on a global positioning system (GPS) is rapidly increasing.
The navigation system includes three or more GPS satellites, a GPS receiver for receiving a position signal and/or an absolute time signal (GPS signal) of each satellite from the three or more GPS satellites, and a navigation terminal having map data inclusive of roads, buildings, mountains, and rivers of a whole country, and calculating a self-position from the received GPS signals, mapping the calculated self-position to the map data, and displaying the mapped self-position.
The navigation system receives a via and a destination from the user, selects a running path from a current position to the destination by a preset path selection method, maps the path to the map data, displays the mapped path, and guides a direction of the navigation terminal running to the destination centering on the path. The path selection method employs a shortest-distance path selection method, an expressway-centered selection method, and a national road-centered selection method.
In general, the navigation terminal of the navigation system is installed in a car, and performs road guidance so that the user can drive the car to the destination fast and conveniently.
As described above, the conventional navigation system is advantageous that, even when the user, that is, a driver does not know a way to the destination, it can display a self-position on a map and perform the road guidance to the destination, thereby providing a convenience.
However, the conventional navigation system displays only the self-position on the map and thus, causes the following drawbacks.
The first drawback is that several persons collectively move riding on the cars not equipped with the navigation terminals or some equipped with the navigation terminals and thus, while they drive to the destination, a preceding vehicle should pay attention to a following vehicle so that the following vehicle does not miss the preceding vehicle, and the following vehicle should pay much attention to the preceding vehicle so that it does not miss the preceding vehicle. Further, the following vehicle is excessively driven not to miss the preceding vehicle and thus, violates a traffic signal.
The second drawback is that, in case where all the cars are equipped with the navigation system, the user should input the destination and set the path to each navigation terminal installed in the car, however, since the paths selected by the respective vehicles can be differentiated at the time of setting the paths, a time taken to arrive at the destination can be differentiated, and since it cannot be recognized that other vehicles run in any area on the path to the destination, it is difficult to do a collective action in driving the car.